Trigger switch with automatic kick-off



Oct. 15, 1957 I D. w. JOHNSON 2,810,051

' TRIGGER SWITCH WITH AUTOMATIC KICK-OFF IN VEN TOR.

40 l 33 0 22 /6 av/o' W Johnson 26 BY /7/$ aflorneys TRIGGER swrrcn wrrn AUTOMATIC rncK-orr David W. Johnson, Newington, Conn., assignor to The Arrow-Hart & Hegeman Electric Company, Hartford, Conn, a corporation of Connecticut Application March 7, 1956,5erial No. 570,097

11 Claims. (Cl- 200-169) This invention relates to electric switches. More particularly, it relates to a switch operated by pressing on a trigger or finger piece to move switch contacts between 011 and E positions and which can also be automatically kicked-off or returned to Ofi or original position by the striking of the latch memberto disconnect the trigger from the operating mechanism which thereupon returns under spring biasing action to its original position.

Itis an object of the invention to provide a trigger operated switch with means which will automatically cause return of the switch to original or Off position upon a machine part or other moving member or means striking or pressing upon an extending latch or part.

Another object of the invention is to provide a switch of the aforementioned type which can be made economically mainly from stamped sheet metal or other readily formed parts and which will be durable and reliable for long usage.

Another object of the invention is to provide a switch of the foregoing type and possessing the foregoing advantages which can be operated manually in the usual manner of operation of trigger switches when the automatic releasing means is not actuated.

Another'object of the invention is to provide a switch mechanism of the foregoing type which will automatically reset itself for the next manual operation upon return of the trigger mechanism through the original or starting position upon release of manual pressure.

Another object is to provide operating mechanism of the aforementioned type which may be applied to conventional or standard switches without the need to redesign or create new contact structures or contact-moving mechanisms.

Other objects and advantages of the invention will become apparent as it is described in connection with the accompanying drawing.

In the drawing:

Fig. 1 is a side elevation view of a switch embodying the invention.

Fig. 2 is a side elevation view, partly broken away, of a switch mechanism similar to Fig. l but with the switch in manually operated position.

Fig. 3 is a bottom view of the switch illustrated in Figs. 1 and 2. I

Fig. 4 is a perspective view of a slider member used in the construction of Figs. 1, 2 and 3.

Fig. 5 is a detailed view of the trigger member used in the construction illustrated in Figs. 1, 2 and 3.

Referring to the drawing, the switching parts are mounted and housed within a molded insulating base it) ofgenerally rectangular shape and hollowed for the reception of the movable and fixed switch contacts. Since the invention may be applied to any conventional switch mechanism, the construction of the fixed and movable contacts and the means for causing movement of the movable contact with a snap action is merely illustrative of one type of common switch mechanism to which the invention may be applied.

As may be seen in Fig. 2, the fixed switch contact 13, a pair of which is mounted side by side edgewise in slots in the base or housing 10, may be engaged and disengaged by the rolling movement of a ball or spherical movable contact 14 which is acted upon by an overcenter compression spring 15. The switch may be moved overcenter in a common and well known manner by a switch operating finger 31 extending into the housing 10 and engaging the upper end of the spring. The member 31 extends down from a slider member, designated generally by the numeral 39, as will hereinafter be more fully described.

Lying on top of the insulating base or housing 10 is a plate 19 which may be stamped from sheet material and extends beyond one end of the casing toward the operating mechanism. On top of the plate 19 a stamped sheet metal frame member, designated generally by the numeral 12, is secured in any suitable fashion as by screwbolts, rivets or otherwise. That portion of the frame member which is over the housing 10 may be of U-shape with out-turned feet or flanges 12b extending laterally from the parallel side walls 12a and 12c so that the flanges are parallel and lie upon the plate 19. The side walls of the frame member are joined by a web or transverse portion lit. The frame 12 at one end covers the top of the housing 10 while at the other end its side walls-12a and extend beyond the housing and Widen divergently upward. 7

Where upward, downward, inward and outward directions are mentioned herein, the reference is to the drawlugs and is not an indication of any limitation upon the invention or mode of operation.

A trigger or finger member 16 is pivotally connected at its upper outer corner (Figs. 1 and 2) to the similar corner of the side walls of the frame by a pivot pin 17 passing transversely through the frame walls and trigger walls- The trigger may be formed by folding into inverted U-shape a blank of sheet metal and then inserting the frame walls between the trigger walls.

Exerting a constant bias in clockwise direction on the trigger member 16 about the pivot pin 17 is a coiled tension spring 25 parallel to and outside the framewall 12a. The spring is anchored at one end by looping through a hole in the plate 19 while its other end connects to a pin 18 transversely mounted in the lower outer corner of the trigger member and extending beyond the side framewall 12a.

Mounted pivotally on a transverse pin 18 between the A parallel walls of the trigger is a flat elongated latch member, designated generally by the numeral 20 and stamped from sheet metal into the form of Fig. 5. At one end, a latch nose 22 extends downward from the latch 20 in position to engage the edge 33 of a transverse portion 53 of a slider member designated generally by the numeral 30, which is hereinafter more fully described.

- The opposite end of the latch 20 has a tail 24 on the opposite side of the pivot pin 13 from the nose 22 and extending outwardly, i. e., in the opposite direction or away from the housing 10. When the tail 24 is struck or pushed in clockwise direction about the pin 18, the nose will move away from and disengage the slider 30.

The-slider 30 is a sheet metal stamping bent into U- shape with side walls 32 and 34 connected by a transverse web portion 33. The slider lies between and parallel to the extensions of the side walls 12a and 120 of the frame. The wall 32 of the slider extends toward and over the housing It and has the aforementioned spring operating finger 51 depending therefrom into the housing for operating the switch.

The opposite end of the wall 32 has a hook formation Patented Oct. 15,. 1957 32a which merges into a semicircular bearing surface 32b against which one end of the pin 18 is pressed by the spring 25. A similar hook formation 34b and bearing surface are formed on the end of the wall 34 in lateral alignment with the bearing 32b for the other end of the pin 18.

Constantly biasing the slider into one position (to the left of Figs. 1 and 2 which is usually switch Oflf position) is a coiled tension spring 49, one end of which is anchored to the transverse portion of the switch frame web 12! by looping through a hole in the center line of the end thereof. The transverse portion 121 of the web is cut away. from a point over the end of the housing, partway toward the outermost end of the frame walls to accommodate the inner end of the spring. The outer end' of the spring 40 is connected to the slider 30 by be ing hooked onto an arm 36 which extends laterally up at the outer end of the slider wall 32. At the arm 36 the slider wall 32' is offset inwardly so that the force of the spring 40 shall be parallel to and midway between the walls 32 and 34 without exerting a substantial sidewise component of force.

From the foregoing the operation of the device may be understood. Upon pressing the trigger 16 from the position of Fig. 1 into the position of Fig. 2, the trigger pivots about its mounting pin 17 and moves the transverse pin 18 in counterclockwise direction about an orbit of which the axis of the pin 17 is the center. Movement of the transverse pin 18 carries the latch member 20 along with it. Since the latch nose 22 is engaged with the edge of the web 33 of the slider 30, the movement of the pin 18 and latch 20 will also cause movement of the slider 30, the three parts thus moving as a unit. Such movement is against the force of both the springs 25 and 40 which are both tensioned additionally by such motion.

The movement of the slider causes its depending switch-operating finger 31 to move into the position of Fig. 2, thus causing the switch spring 15 to move overcenter and operate the movable switch contact 14 from the position it previously occupied.

If at this time pressure upon the trigger member 16 is released, the parts will return as a unit to the original or starting position, namely the position of Fig. 1.

However, if when the parts have been moved into the position of Fig. 2 pressure is exerted upon the tail 24 of the latch 20 causing the latch to pivot about the trans verse pin 18 in a clockwise direction, the latch nose 22 will disengage the slider. Thereupon, the slider will be free to move under the constant bias exerted by the spring 40. The slider will thereupon move to the left (referring to Fig. 2) while the trigger and latch are still held manually in the position of Fig. 2. The movement of the slider will automatically cause the switch to resume its original position.

Upon relieving manual pressure from the trigger 16, the trigger will move under the constant bias of the spring 25 in a clockwise direction, thus causing the pin 18 to move from the position of Fig. 2 to the position of Fig. l and carrying with it the latch 20. During such movement, the latch nose 22 moves over the inner or upper surface of the transverse web portion 33 of the slider until the latch nose 2L2 clears the edge 33'. Before reaching that point, the upper surface of the latch comes into contact with the convolutions of the spring which exert a downward pressure (counterclockwise about pivot 18) on the latch. Thus, as soon as latch nose 22 clears edge 33' the latch nose will again become engaged with such edge and the parts will be ready for a repetition of the foregoing operation whenever manual pressure is again exerted upon the trigger 16.

From the foregoing, it will be clear that the spring 40 serves two functions. It not only stresses the slider 30 for return movement, but it also presses the latch 20 toward position for re-engagement of the slider edge 33' with the latch nose 22.

In order to stop the travel of the slider toward the housing 10, under influence of the springs 40 and 25, a lug 37 laterally extends downwardly from the lower edge of the slider to engage the edge of the plate 19 when the desired length of travel of the slider has been reached.

From the foregoing, it Will be apparent that the invention provides for automatic kick-01f of a trigger-operated electric switch operating mechanism. The automatic kick-off may be caused or actuated by the movement of a machine part, or in any other manner, by exertion of pressure upon the latch tail 24. The invention also pro vides a mechanism which automatically resets itself upon release of the trigger and movement of the parts back to their original position. The invention also provides mechanism which can be readily applied to and used with standard or conventional switches, without the need for redesign or reconstruction of such switches. The invention also is economical to manufacture and assemble since it can readily be made from stamped sheet metal parts.

Many modifications within the scope of the invention will occur to those skilled in the art. Therefore, the invention is not limited to the specific form and configuration of parts as illustrated and described.

What is claimed is:

l. in an electric switch having relatively movable contacts, operating mechanism comprising contact-moving means to cause contact engagement and separation and a rectilinearly movable member, a trigger member, a connecting member between said trigger member and said rectilinearly movable member, said connecting member being engaged with said rectilinearly movable member but disengageable therefrom for movement of said contact-moving means independent of said trigger member, and means biasing said rectilinearly movable member for operating the contact-moving means automatically upon disengagement from said connecting member.

2. In an electric switch having relatively movable contacts, operating mechanism comprising contact-moving means to cause contact engagement and separation and a rectilinearly movable member, a trigger member, a connecting member between said trigger member and said rectilinearly movable member, said connecting member being engaged with said rectilinearly movable member but disengageable therefrom for movement of said contact-moving means independent of said trigger member, and means biasing said rectilinearly movable member in one direction for operating the contact-moving means automatically upon disengagement of said connecting member, and means biasing said trigger member in said one direction, said trigger member returning said rectilinearly movable member as the trigger member returns under stress of its biasing means.

3. An electric switch as claimed in claim 2 in which the biasing means for the rectilinearly movable member moves the connecting member into re-engagement with the rectilinearly movable member as the trigger member returns to said one position.

4. Anelectric switch as claimed in claim 1 in which the biasing means for said rectilinearly movable member engages said connecting member and urges it into reengagement with said rectilinearly movable member as said trigger member is released, after disengagement of the connecting member from the rectilinearly movable member.

5. An electric switch as claimed in claim 1 in which the biasing means for the rectilinearly movable member is in the same plane as the connecting member and presses the latter toward engagement with the rectilinearly movable member.

6. An electric switch as claimed in claim 2 wherein both biasing means act to operate the contacts when the connecting member is engaged with the rectilinearly movable member and the trigger member is released after manual actuation.

7 In an electric switch, fixed and movable contacts,

means to cause engagement and separation of said contacts including an actuator, a manually movable trigger, a latch pivotally mounted on the trigger and engageable with the actuator, to cause unitary movement of the trigger, latch and actuator when the trigger is manually operated, said latch having an extension strikeable to disengage said latch from said actuator, a dual-function spring biasing said actuator for operation independent of said trigger when said latch is struck and also biasing said latch toward engagement with said actuator on return movement of the latch and trigger.

8. An electric switch as claimed in claim 7 having a return spring acting on said trigger to return it to unactuated position when manual pressure is released, in which position said latch automatically re-engages said actuator.

9. In an electric switch having relatively movable contacts, operating mechanism comprising means to cause contact engagement and separation, a manually operable lever, contact actuating means, connecting means between said trigger member and said contact-actuating means, said connecting means being engaged with said contactactuating means but disengageable therefrom for movement of said contact-actuating means independent of said manually operable member, and a dual-function spring biasing said contact-actuating means toward unoperated position and biasing said connecting means toward engagement with said contact-actuating means.

10. An electric switch as claimed in claim 9 wherein the spring acts axially in exerting bias on said contactactuating means and acts laterally in exerting bias on said connecting means.

11. An electric switch as claimed in claim 7 in which the spring acts axially on said actuator and laterally on said latch.

References Cited in the file of this patent UNITED STATES PATENTS 698,096 Ball Apr. 22, 1902 1,218,059 Cope Mar. 6, 1917 1,421,740 Stevens July 4, 1922 2,385,292 Logan Sept. 18, 1945 2,414,343 Stoeck et a1. Jan. 14, 1947 

